一個應用被用戶卸載肯定是有理由的,而開發者卻未必能得知這一重要的理由,畢竟用戶很少會主動反饋建議,多半就是用得不爽就卸,如果能在被卸載后獲取到用戶的一些反饋,那對開發者進一步改進應用是非常有利的。目前據我所知,國內的Android應用中實現這一功能的只有360手機衛士、360平板衛士,那么如何實現這一功能的?
我們可以把實現卸載反饋的問題轉化為監聽自己是否被卸載,只有得知自己被卸載,才可以設計相應的反饋處理流程。以下的列表是我在研究這一問題的思路:
1,注冊BroadcastReceiver,監聽"android.intent.action.PACKAGE_REMOVED"系統廣播
結果:NO。未寫代碼,直接分析,卸載的第一步就是退出當前應用的主進程,而此廣播是在已經卸載完成后才發出的,此時主進程都沒有了,去哪onReceive()呢?
2,若能收到"將要卸載XX包"的系統廣播,在主進程被退出之前就搶先進行反饋處理就好了,可惜沒有這樣的系統廣播,不過經過調研,倒是發現了一個辦法,讀取系統log,當日志中包含"android.intent.action.DELETE"和自己的包名時,意味着自己將要被卸載。
結果:NO。調試時發現此方法有兩個缺陷,(1)點擊設置中的卸載按鈕即發出此Intent,此時用戶尚未在彈框中確認卸載;(2)pm命令卸載不出發此Intent,意味着被諸如手機安全管家,豌豆莢等軟件卸載時,無法提前得知卸載意圖。
3,由於時間點不容易把控,所以干脆不依賴系統廣播或log,考慮到卸載過程會刪除"/data/data/包名"目錄,我們可以用線程直接輪詢這個目錄是否存在,以此為依據判斷自己是否被卸載。
結果:NO。同方法1,主進程退出,相應的線程必定退出,線程還沒等到判斷目錄是否存在就已經被銷毀了。
4,改用C端進程輪詢"/data/data/包名"目錄是否存在
結果:YES。借助Java端進程fork出來的C端進程在應用被卸載后不會被銷毀。
OK,上代碼!
Activity啟動時fork出C端進程輪詢目錄:
1 package main.activity; 2 3 import pym.test.uninstalledmoniter.R; 4 import android.app.Activity; 5 import android.os.Bundle; 6 import android.util.Log; 7 8 /** 9 * @author pengyiming 10 * @note 監聽此應用是否被卸載,若被卸載則彈出卸載反饋 11 * 12 */ 13 14 public class UninstalledMoniterActivity extends Activity 15 { 16 /* 數據段begin */ 17 private static final String TAG = "UninstalledMoniterActivity"; 18 /* 數據段end */ 19 20 /* 函數段begin */ 21 private native void init(); 22 static 23 { 24 Log.d(TAG, "load libuninstalled_moniter"); 25 System.loadLibrary("uninstalled_moniter"); 26 } 27 28 @Override 29 public void onCreate(Bundle savedInstanceState) 30 { 31 super.onCreate(savedInstanceState); 32 Log.d(TAG, "onCreate"); 33 34 setContentView(R.layout.uninstalled_moniter_layout); 35 36 init(); 37 } 38 /* 函數段end */ 39 }
核心——native方法頭文件:
1 /* 頭文件begin */ 2 #include <jni.h> 3 #include <stdio.h> 4 #include <string.h> 5 #include <android/log.h> 6 #include <unistd.h> 7 /* 頭文件end */ 8 9 /* 宏定義begin */ 10 //清0宏 11 #define MEM_ZERO(pDest, destSize) memset(pDest, 0, destSize) 12 13 //LOG宏定義 14 #define LOG_INFO(tag, msg) __android_log_write(ANDROID_LOG_INFO, tag, msg) 15 #define LOG_DEBUG(tag, msg) __android_log_write(ANDROID_LOG_DEBUG, tag, msg) 16 #define LOG_WARN(tag, msg) __android_log_write(ANDROID_LOG_WARN, tag, msg) 17 #define LOG_ERROR(tag, msg) __android_log_write(ANDROID_LOG_ERROR, tag, msg) 18 /* 宏定義end */ 19 20 #ifndef _Included_main_activity_UninstalledMoniterActivity 21 #define _Included_main_activity_UninstalledMoniterActivity 22 #ifdef __cplusplus 23 extern "C" { 24 #endif 25 26 #undef main_activity_UninstalledMoniterActivity_MODE_PRIVATE 27 #define main_activity_UninstalledMoniterActivity_MODE_PRIVATE 0L 28 #undef main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE 29 #define main_activity_UninstalledMoniterActivity_MODE_WORLD_READABLE 1L 30 #undef main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE 31 #define main_activity_UninstalledMoniterActivity_MODE_WORLD_WRITEABLE 2L 32 #undef main_activity_UninstalledMoniterActivity_MODE_APPEND 33 #define main_activity_UninstalledMoniterActivity_MODE_APPEND 32768L 34 #undef main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS 35 #define main_activity_UninstalledMoniterActivity_MODE_MULTI_PROCESS 4L 36 #undef main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE 37 #define main_activity_UninstalledMoniterActivity_BIND_AUTO_CREATE 1L 38 #undef main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND 39 #define main_activity_UninstalledMoniterActivity_BIND_DEBUG_UNBIND 2L 40 #undef main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND 41 #define main_activity_UninstalledMoniterActivity_BIND_NOT_FOREGROUND 4L 42 #undef main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT 43 #define main_activity_UninstalledMoniterActivity_BIND_ABOVE_CLIENT 8L 44 #undef main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT 45 #define main_activity_UninstalledMoniterActivity_BIND_ALLOW_OOM_MANAGEMENT 16L 46 #undef main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY 47 #define main_activity_UninstalledMoniterActivity_BIND_WAIVE_PRIORITY 32L 48 #undef main_activity_UninstalledMoniterActivity_BIND_IMPORTANT 49 #define main_activity_UninstalledMoniterActivity_BIND_IMPORTANT 64L 50 #undef main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY 51 #define main_activity_UninstalledMoniterActivity_BIND_ADJUST_WITH_ACTIVITY 128L 52 #undef main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE 53 #define main_activity_UninstalledMoniterActivity_CONTEXT_INCLUDE_CODE 1L 54 #undef main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY 55 #define main_activity_UninstalledMoniterActivity_CONTEXT_IGNORE_SECURITY 2L 56 #undef main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED 57 #define main_activity_UninstalledMoniterActivity_CONTEXT_RESTRICTED 4L 58 #undef main_activity_UninstalledMoniterActivity_RESULT_CANCELED 59 #define main_activity_UninstalledMoniterActivity_RESULT_CANCELED 0L 60 #undef main_activity_UninstalledMoniterActivity_RESULT_OK 61 #define main_activity_UninstalledMoniterActivity_RESULT_OK -1L 62 #undef main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER 63 #define main_activity_UninstalledMoniterActivity_RESULT_FIRST_USER 1L 64 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE 65 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DISABLE 0L 66 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER 67 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_DIALER 1L 68 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT 69 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SHORTCUT 2L 70 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL 71 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_LOCAL 3L 72 #undef main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL 73 #define main_activity_UninstalledMoniterActivity_DEFAULT_KEYS_SEARCH_GLOBAL 4L 74 75 /* 76 * Class: main_activity_UninstalledMoniterActivity 77 * Method: init 78 * Signature: ()V 79 */ 80 JNIEXPORT void JNICALL Java_main_activity_UninstalledMoniterActivity_init(JNIEnv *, jobject); 81 82 #ifdef __cplusplus 83 } 84 #endif 85 #endif
核心——native方法實現:
1 /* 頭文件begin */ 2 #include "main_activity_UninstalledMoniterActivity.h" 3 /* 頭文件end */ 4 5 #ifdef __cplusplus 6 extern "C" { 7 #endif 8 9 /* 內全局變量begin */ 10 static char c_TAG[] = "UninstalledMoniterActivity.init"; 11 static jboolean b_IS_COPY = JNI_TRUE; 12 /* 內全局變量 */ 13 14 /* 15 * Class: main_activity_UninstalledMoniterActivity 16 * Method: init 17 * Signature: ()V 18 */ 19 JNIEXPORT void JNICALL Java_main_activity_UninstalledMoniterActivity_init(JNIEnv *env, jobject obj) 20 { 21 jstring tag = (*env)->NewStringUTF(env, c_TAG); 22 23 //初始化log 24 LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY) 25 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "init OK"), &b_IS_COPY)); 26 27 //fork子進程,以執行輪詢任務 28 pid_t pid = fork(); 29 if (pid < 0) 30 { 31 //出錯log 32 LOG_ERROR((*env)->GetStringUTFChars(env, tag, &b_IS_COPY) 33 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "fork error !!!"), &b_IS_COPY)); 34 } 35 else if (pid == 0) 36 { 37 //子進程輪詢"/data/data/pym.test.uninstalledmoniter"目錄是否存在,若不存在則說明已被卸載 38 while (1) 39 { 40 FILE *p_file = fopen("/data/data/pym.test.uninstalledmoniter", "r"); 41 if (p_file != NULL) 42 { 43 fclose(p_file); 44 45 //目錄存在log 46 LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY) 47 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "I'm OK !!!"), &b_IS_COPY)); 48 49 sleep(1); 50 } 51 else 52 { 53 //目錄不存在log 54 LOG_DEBUG((*env)->GetStringUTFChars(env, tag, &b_IS_COPY) 55 , (*env)->GetStringUTFChars(env, (*env)->NewStringUTF(env, "I'm NOT OK !!!"), &b_IS_COPY)); 56 57 //執行命令am start -a android.intent.action.VIEW -d http://shouji.360.cn/web/uninstall/uninstall.html 58 execlp("am", "am", "start", "-a", "android.intent.action.VIEW", "-d", "http://shouji.360.cn/web/uninstall/uninstall.html", (char *)NULL); 59 } 60 } 61 } 62 else 63 { 64 //父進程直接退出,使子進程被init進程領養,以避免子進程僵死 65 } 66 } 67 68 #ifdef __cplusplus 69 } 70 #endif
注1:為了調試方便,包含<android/log.h>,使得so在執行過程中也可以像Java端一樣方便得打出log。相應的mk文件需要加上以下兩句聲明
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
LOCAL_LDLIBS += -L$(SYSROOT)/usr/lib -llog
注2:代碼中引用了360手機衛士的反饋地址,僅供大家學習、測試使用~~~